In certain closed box electronic systems it has become common practice for the consumer to open the box and add printed wiring boards or other devices to the existing wiring boards. Such additions are not always easy, even for trained service personnel. When untrained consumers attempt such operations many problems can result. One such problem, of course, is the always present danger of electrical shock or accidental miswiring resulting in a fire or other mishap.
As the box which houses the electronic circuitry becomes reduced in size the tolerance for error becomes even less and thus the potential for serious problems increases. In addition, since the amount of available room within the box is severely limited, it is often impossible for a consumer to add additional expansion boards without first removing many of the bulky parts from the housing. In desk top computers these bulky parts are typically power supplies and disk drives, two component types which are difficult to remove and frought with trouble unless reconnected properly.
A related problem, but one which arises in a different context, is the ability of the equipment manufacturer to remove the basic electronics from the housing for repair or servicing. When a number of extra boards have been added, the time necessary to remove them all adds considerably to the repair cost. An alternative would be for the manufacturer to build all of the electronic functions on a single board. This approach, however, would result in higher initial costs and a reduced ability to tailor a system specifically to a consumer's requirements.
Thus, a need exists in the art for an arrangement which allows many add-on electronic boards to be inserted into, or removed from, a closed electronics system housing with a minimum of effort and with a minimum of possible error.
It is also desirous to arrange such a system such that add-on boards can be removed easily thereby allowing access to the main electronic components.
It is also a desired result to allow for the easy addition and removal of such add-on boards packed in a high density while also providing for rigid support of the boards.